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1.
64层螺旋CT测量心外膜脂肪体积:对测量结果的可重复性研究 总被引:1,自引:0,他引:1
目的:评价不同医师在R-R间期不同相位窗对64层螺旋CT心外膜脂肪组织(EAT)体积的测量结果的影响。方法:搜集23例行CT冠状动脉成像的患者,由两名有经验的影像科医师采用后处理软件分别测量钙化积分图像收缩期相(R-R间期20%~35%相位)和舒张期相(R-R间期65%~80%相位)的EAT体积。比较不同医师、不同相位窗对EAT体积测量结果的影响。结果:不同医师、不同相位窗所测得EAT体积均有较好的可重复性。相同医师不同相位窗所测95%一致性界限分别为(-4.326,3.794)、(-2.679,3.781);而相同相位窗不同医师所测95%一致性界限分别为收缩期相位窗(-6.205,7.480)、舒张期相位窗(-4.425,7.334),舒张期相所测95%一致性界限范围要小于收缩期相。结论:64层螺旋CT进行EAT定量时,EAT体积的测量有很好的可重复性,其中舒张期相进行测量可重复性更好。 相似文献
2.
Quantification of epicardial adipose tissue using 64-slice CT:a study on the reproducibility of the measurement 下载免费PDF全文
《放射学实践》2012,27(8)
目的:评价不同医师在R-R间期不同相位窗对64层螺旋CT心外膜脂肪组织(EAT)体积的测量结果的影 响.方法:搜集23例行CT冠状动脉成像的患者,由两名有经验的影像科医师采用后处理软件分别测量钙化积分图像收 缩期相(R-R间期20%~35%相位)和舒张期相(R-R间期65%~80%相位)的EAT体积.比较不同医师、不同相位窗对 EAT体积测量结果的影响.结果:不同医师、不同相位窗所测得EAT体积均有较好的可重复性.相同医师不同相位窗 所测95%一致性界限分别为(-4.326,3.794)、(-2.679,3.781);而相同相位窗不同医师所测95%一致性界限分别为收 缩期相位窗(-6.205,7.480)、舒张期相位窗(-4.425,7.334),舒张期相所测95%一致性界限范围要小于收缩期相.结论:64层螺旋CT进行EAT定量时,EAT体积的测量有很好的可重复性,其中舒张期相进行测量可重复性更好. 相似文献
3.
三种测量方法对肺部不同密度小结节CT体积测量的观察 总被引:1,自引:0,他引:1
目的 评价肺部不同密度小结节CT体积测量 3种方法 (固定阈值法、可变阈值法和部分容积法 )的可重复性。方法 选择 6个 3种不同密度 (实性、部分实性、非实性 )小结节 ,由 5位医生独立采用上述 3种体积测量方法分别测量计算体积 5次 ,ANOVA方差分析医生之间各种方法对不同密度结节体积测量的可重复性。结果 固定阈值法对于实性结节的体积测量可重复性好 (P >0 0 5 ) ,误差小于± 2 %;部分实性结节 (CT值 - 70 0~ 4 0HU)仅识别其中实性部分 ;非实性结节 (CT值- 80 0~ - 4 0 0HU)识别不出来。可变阈值法选择适当的CT阈值范围 ,标记测量的范围与病变重叠良好 ,主要适用于部分实性结节和非实性结节的体积测量 ,但可重复性不好 (P <0 0 5 ) ,误差范围 <±1 0 %(99%的可信区间 - 1 2 %~ 36 %)。通过CT阈值与体积变化关系的实验发现 :单纯实性结节CT值的阈值范围为 - 4 0 0~ 2 0 0HU ,单纯非实性结节为 - 80 0~ 0HU ,部分实性结节为 - 80 0~ 2 0 0HU。部分容积法对于密度均匀的实性结节和非实性结节 ,医生之间有较好的可重复性 (P >0 0 5 ) ,但对于其他结节医生之间的可重复性不佳 (P <0 0 5 ) ,误差范围 - 2 0 %~ 4 0 %(99%的可信区间 - 30 %~ 5 0 %)。各种体积测量方法之间的体积无可比性 ,误 相似文献
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孤立性肺结节CT动态增强扫描的层面优化及临床应用 总被引:5,自引:0,他引:5
目的利用选层重组的方法改善孤立性肺结节(SPN)CT动态增强扫描各延时像测量层面的一致性,并探讨其临床应用价值。方法(1)对3种均质液体行CT螺旋扫描并在Z轴方向同层厚任意多平面重组,比较其原始扫描图像及重组图像密度测量值的差异。(2)对72例SPN患者行螺旋CT动态增强扫描,运用一定的选层重组的方法保证各延时像测量层面的一致性。并对其中46例经病理及临床证实的SPN的CT动态增强特点进行评价,评估其增强前后的CT值、强化峰值、SPN与主动脉的强化值比。结果(1)不同密度的均质液体同层厚的原始扫描图像及重组图像间密度测量值差异无统计学意义(F=1.544,P>0.05);(2)67例SPN选层重组前、后各延时像测量层面一致率分别为20.98%(14/67)和97.01%(65/67),其差异有统计学意义(χ2=80.22,P=0.00)。多层螺旋CT对5例SPN的选层重组全部成功。(3)SPN的CT动态增强各延时像测量层面一致性优化以后,恶性结节与炎性结节强化峰值[(38.48±14.32)、(42.48±11.55)HU]和结节与主动脉强化值比[(19.64±9.52)、(21.14±7.77)%]均明显高于良性结节[(9.52±3.78)HU、(3.41±1.86)%];P值均<0.01。炎性结节的强化峰值、结节与主动脉强化值比[(42.48±11.55)HU、(21.14±7.77)%]与恶性结节[(38.48±14.32)HU、(19.64±9.52)%]间的差异无统计学意义(P值均>0.05)。CT动态增强选层重组保证各延时像测量层面一致性后,使其对SPN定性的准确率由78%提升至80%。结论螺旋CT扫描Z轴方向同层厚任意重组对均质物质的密度值的测量无明显影响。CT动态增强扫描各延时像测量层面一致性的优化可进一步客观反映SPN的动态增强情况,有利于其形态学的比较及CT值的测量,有望提高其对孤立性肺结节鉴别诊断的能力。 相似文献
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6.
多层螺旋CT测量胰腺体积的准确性评价 总被引:1,自引:0,他引:1
目的研究多层螺旋CT测量胰腺体积的准确性。资料与方法多层螺旋CT扫描胰腺模型及胰腺正常患有其他疾病的患者,由有5年以上CT工作经验的放射科医师测量胰腺体积并记录。结果胰腺模型体积CT测量值与实际值差异无统计学意义(t=1.648,P=0.134),这两者间的一致性很高(ICC=1.000,P=0.000);可重复性分析中,CT测量胰腺体积观察者内的差异及观察者间的差异无统计学意义(P>0.05),一致性很高(所有ICC>0.99,P=0.000)。结论多层螺旋CT测量胰腺体积准确、可靠,可重复性较高。 相似文献
7.
目的:基于胸部模体探讨不同强度深度学习重建算法(DLIR)对低剂量CT图像上肺结节显示及测量的影响。方法:采用包括纵隔、支气管血管束、软组织及骨骼的成年男性胸部仿真模型,内置直径(体积)为5 mm(66 mm3)、8 mm(268 mm3)和10 mm(523 mm3)的实性结节(SN)及磨玻璃结节(GGN),对其进行低剂量CT扫描(100 kVp、40 mA,CTDIVOI=0.84 mGy),采用标准卷积核的自适应统计迭代重建算法(ASIR-V)及中档(DLIR-M)和高档(DLIR-H)深度学习重建算法分别进行图像重建。在肺组织内放置ROI(面积100 mm2)测量肺组织CT值的标准差(SD)作为肺组织噪声(N肺组织)。选用肺结节CT影像辅助检测系统自动计算得到10 mm SN及10 mm GGN CT值的SD(即N结节)。计算3组图像上肺组织以及直径10 mm的SN和GGN的信噪比(SNR)及对比噪声比(CNR),以及所有结节... 相似文献
8.
64层螺旋CT低剂量扫描检测肺小结节敏感性的实验研究 总被引:1,自引:0,他引:1
目的 探讨64层螺旋CT胸部低剂量扫描对大小、密度不同肺小结节的检测敏感性及最优扫描参数. 方法 制作3组不同密度(软组织密度、较低密度、磨玻璃密度)、直径13~2.5 mm的人工肺结节,置于组织等效胸部模型中,使用Philips Brilliance 64层CT机以常规剂量(管电压120 kV,管电流250 mAs)和低剂量(管电压120 kV,管电流50、30 mAs和21 mAs)分别扫描.测量、记录剂量指标(CTDIw和DLP)、模型各部位CT值、CT值标准差,评估各组结节的可见度. 结果 64层螺旋CT采用低剂量扫描(21~50 mAs)的辐射剂量为常规剂量(250 mAs)的8%~20%.不同扫描剂量条件下模型各部位CT值差异无统计学意义(P>0.05);而CT值标准差差异有统计学意义(P<0.001)且随电流降低而增加.各组结节中仅2.5 mm和4 mm磨玻璃密度(-600 HU左右)结节在管电流21 mAs扫描时出现不可见情况. 结论 64层螺旋CT实验条件下30 mAs低剂量扫描最小直径2.5 mm磨玻璃密度结节,是最优扫描参数. 相似文献
9.
目的探讨低剂量及常规剂量螺旋CT扫描在检出磨玻璃密度肺结节(ground-glass nodule,GGN)的数目、边缘、内部结构与周边结构是否在统计学上存在显著差异。方法对经常规剂量(200mA)与层厚(5mm)螺旋CT扫描发现GGN患者56例同时行肺部低剂量(30mA)螺旋CT扫描,所得图像分别重建2mm、1mm,并按结节直径5mm,5~10mm,10mm不同大小分组,记录结节数目、边缘、内部特征以及周边结构等。结果低剂量与常规剂量螺旋CT扫描在检出GGN的数目、边缘、内部结构与周边结构无统计学意义。结论30mA低剂量螺旋CT扫描及层厚2mm可对GGN作出较好的判断,值得在早期肺癌筛查中应用。 相似文献
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64排CT肺结节三维体积测量与二维测量的比较研究 总被引:2,自引:1,他引:1
目的 比较64排螺旋CT对肺结节三维体积测量与二维直径测量的准确性.方法 选取接受64排螺旋CT(64-de-tector spiral CT,MDCT)胸部扫描并发现实性肺结节的病人33例(女18例,男15例),共60个实性结节(直径<3 cm).2名医师独立阅片,在GE AW4.2工作站上利用高级肺结节分析软件(ALA)进行肺结节自动分离,记录其体积数值,均各测3次,并选择肺结节轴位最大截面测量长度及宽度,共测2次,前后间隔1月.用Bland and Ahman方法及相关系数评价测试者问一致性及测试者本身重复性.并评价三维体积测量与二维直径测量结果间是否存在差异性.结果 57个结节成功分离,3个分离失败或明显错误,分离成功率95%.两测试者问体积测量结果一致性好,r为0.998,比两测试者间直径测量结果的一致性要好(r=0.974).经检验,2个相关系数差别具有统计学意义.对于小结节(直径<10 mm)或孤立型及血管旁型肺结节,三维体积测量表现出了很好的重复性.结论 64排CT对肺结节三维体积测量比二维测量方法更具准确性,尤其对于小结节、孤立型及血管型结节. 相似文献
11.
Hyungjin Kim Chang Min Park Sang Min Lee Hyun-Ju Lee Jin Mo Goo 《Korean journal of radiology》2013,14(4):683-691
Objective
To compare the segmentation capability of the 2 currently available commercial volumetry software programs with specific segmentation algorithms for pulmonary ground-glass nodules (GGNs) and to assess their measurement accuracy.Materials and Methods
In this study, 55 patients with 66 GGNs underwent unenhanced low-dose CT. GGN segmentation was performed by using 2 volumetry software programs (LungCARE, Siemens Healthcare; LungVCAR, GE Healthcare). Successful nodule segmentation was assessed visually and morphologic features of GGNs were evaluated to determine factors affecting segmentation by both types of software. In addition, the measurement accuracy of the software programs was investigated by using an anthropomorphic chest phantom containing simulated GGNs.Results
The successful nodule segmentation rate was significantly higher in LungCARE (90.9%) than in LungVCAR (72.7%) (p = 0.012). Vascular attachment was a negatively influencing morphologic feature of nodule segmentation for both software programs. As for measurement accuracy, mean relative volume measurement errors in nodules ≥ 10 mm were 14.89% with LungCARE and 19.96% with LungVCAR. The mean relative attenuation measurement errors in nodules ≥ 10 mm were 3.03% with LungCARE and 5.12% with LungVCAR.Conclusion
LungCARE shows significantly higher segmentation success rates than LungVCAR. Measurement accuracy of volume and attenuation of GGNs is acceptable in GGNs ≥ 10 mm by both software programs. 相似文献12.
由于医学成像技术的迅速发展,CT得到了广泛普及应用。随着肺结节检出率的提高,人们对肺小结节尤其是磨玻璃结节也有了进一步的认识。相比实性结节,磨玻璃结节虽然生长缓慢,但它的恶性率却高于实性肺结节,诊断难度大,尤其是持续存在的纯磨玻璃结节,由于缺乏特异征象,其诊断难度更高,且与早期肺癌相关性较大,故对纯磨玻璃结节的CT研究具有重要的临床价值。就纯磨玻璃结节的定义、病理特征及CT研究进展进行综述。 相似文献
13.
Das M Mühlenbruch G Katoh M Bakai A Salganicoff M Stanzel S Mahnken AH Günther RW Wildberger JE 《Investigative radiology》2007,42(5):297-302
OBJECTIVES: The accuracy of automated volumetry for pulmonary nodules in a phantom using different CT scanner technologies from single-slice spiral CT (SSCT) to 64-slice multidetector-row CT (MDCT) was compared. MATERIALS AND METHODS: A lung phantom with 5 different categories of pulmonary nodules was scanned using a single-slice spiral CT, a 4-slice MDCT, a 16-slice MDCT and a 64-slice MDCT. Each category comprised of 7-9 nodules each (total n = 40) with different known volumes. Standard dose and low dose protocols were performed using thin and thick collimation. Image data were reconstructed at the thinnest slice thickness. Data sets were analyzed with a dedicated volumetry software. Volumes of all nodules were calculated and compared. RESULTS: Mean absolute percentage error (APE) for all nodules was 8.65% (+/-7.29%) for the SSCT, 10.26% (+/-8.25%) for the 4-slice MDCT, 8.19% (+/-7.57%) for the 16-slice MDCT and 7.89% (+/-7.39%) for the 64-slice MDCT. There was statistically significant influence of the scanner type, protocol, anatomic location, and nodule volume on APE, but overall, APEs were comparable. CONCLUSION: Computer-aided volumetry showed accurate measurements in all tested scanner types. This finding has important implications for nodule assessment and follow-up. 相似文献
14.
Ming Li Gang Shen Feng Gao Xiangpeng Zheng Yanqing Hua Li Xiao 《Diagnostic and interventional radiology (Ankara, Turkey)》2015,21(5):391-396
PURPOSE
We aimed to explore the value of localizing small ground-glass nodules (GGNs; <10 mm) or multiple GGNs within the same lobe in re-aerated lung specimens using CT-guided fine-needle localization.METHODS
Thirty-five lung specimens containing single small GGNs (<10 mm) and eight specimens containing two or more GGNs in the same lobe were re-aerated with an inflatable aerator. All lesions were localized via CT-guided fine-needle localization following re-aeration. The specimens were then sent for pathologic sampling and qualitative diagnosis.RESULTS
All 69 nodules from 43 cases were successfully localized using CT-guided fine-needle localization following re-aeration.CONCLUSIONS
CT-guided fine-needle localization of lesions in surgical specimens under constant, moderate mechanical aeration allows for the rapid and accurate localization of lesions and helps avoid damage from preoperative localization.In 2011, the International Association for the Study of Lung Cancer, the American Thoracic Society, and the European Respiratory Society proposed a new classification for lung adenocarcinomas. The new classification system fully affirmed the role of preoperative computed tomography (CT) examinations in the diagnosis of early-staged lung cancer; the data provided by studies using the new classification system indicate that the lymph node metastasis rates for adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) are extremely low and that patients are expected to have 100% or nearly 100% disease-specific survival following complete resections (1). With the rapid development of multidetector spiral CT (MDCT) and video-assisted thoracoscopic surgery (VATS), not only can small pulmonary nodules be detected clearly but also more and more patients with small nodules that are highly suspicious of lung cancer can be cured with minimally invasive surgery. Atypical adenomatous hyperplasia (AAH), AIS, and MIA often present as pure ground-glass nodules (pGGNs) or mixed ground-glass nodules (mGGNs) containing small amounts of solid elements that are detected on CT images; the diameter of such nodules is often less than 10 mm, and early intervention can improve the prognoses of patients with these lesions. However, it is widely known that these lesions, which are small in volume and low in density, can be extremely difficult to accurately position during surgery and in surgically resected specimens, leading to problems for both thoracic surgeons and pathologists. In addition, it is much more difficult for pathologists to localize all lesions without CT-guided fine-needle localization when two or more GGNs are present in the same lobe. In such cases, the localization of all the GGNs is crucial because the pathologic diagnosis (including gene mutations) of each nodule could help to guide subsequent treatments (1, 2). The aim of this study was to analyze the value of CT-guided fine-needle positioning of lesions that presented as GGNs on CT images under constant, moderate mechanical aeration of the surgical specimens. To the best of our knowledge, this is the first study describing needle localization of small lung nodules in postoperative specimens. 相似文献15.
E. Baratella A.M. Bozzato C. Marrocchio C. Natali A. Di Giusto E. Quaia M.A. Cova 《Radiography》2021,27(2):574-580
IntroductionGround-glass nodules may be the expression of benign conditions, pre-invasive lesions or malignancies. The aim of our study was to evaluate the capability of chest digital tomosynthesis (DTS) in detecting pulmonary ground-glass opacities (GGOs).MethodsAn anthropomorphic chest phantom and synthetic nodules were used to simulate pulmonary ground-glass nodules. The nodules were positioned in 3 different regions (apex, hilum and basal); then the phantom was scanned by multi-detector CT (MDCT) and DTS. For each set (nodule-free phantom, nodule in apical zone, nodule in hilar zone, nodule in basal zone) seven different scans (n = 28) were performed varying the following technical parameters: Cu-filter (0.1–0.3 mm), dose rateo (10–25) and X-ray tube voltage (105–125 kVp). Two radiologists in consensus evaluated the DTS images and provided in agreement a visual score: 1 for unidentifiable nodules, 2 for poorly identifiable nodules, 3 for nodules identifiable with fair certainty, 4 for nodules identifiable with absolute certainty.ResultsIncreasing the dose rateo from 10 to 15, GGOs located in the apex and in the basal zone were better identified (from a score = 2 to a score = 3). GGOs located in the hilar zone were not visible even with a higher dose rate. Intermediate density GGOs had a good visibility score (score = 3) and it did not improve by varying technical parameters. A progressive increase of voltage (from 105 kVp to 125 kVp) did not provide a better nodule visibility.ConclusionDTS with optimized technical parameters can identify GGOs, in particular those with a diameter greater than 10 mm.Implications for practiceDTS could have a role in the follow-up of patients with known GGOs identified in lung apex or base region. 相似文献
16.
Yu Zhang Yan Shen Jin Wei Qiang Jian Ding Ye Jie Zhang Rui Ying Zhao 《European radiology》2016,26(9):2921-2928
Objective
To investigate the high-resolution computed tomography (HRCT) features that distinguish lung adenocarcinomas in situ (AISs) and minimally invasive adenocarcinomas (MIAs) from invasive adenocarcinomas (IACs) appearing as ground-glass nodules (GGNs), and to select candidates for sublobar resection.Methods
Two hundred and twenty-nine patients with 237 GGNs of less than 2 cm (139 AIS-MIA nodules and 98 IAC nodules) confirmed by surgery and pathology were retrospectively reviewed. The HRCT features of the AIS-MIAs and IACs were analysed and compared. Receiver operating characteristic (ROC) analyses were conducted to determine the cutoff values for the qualitative variables and their diagnostic performances.Results
Significant differences were found in the density, nodule and solid component diameters, CT values of the ground-glass and solid components, lobulated shape, spiculated margin, abnormal pulmonary vein and artery, air bronchogram, and pleural indentation of the GGNs between the two groups. Multivariate and ROC analyses revealed that larger diameter of nodules (≥12.2 mm) and solid components (≥6.7 mm), and higher CT values of the solid components (≥ -192 HU) in the GGNs with air bronchogram were significantly associated with IACs.Conclusions
HRCT can identify distinguishing morphological features between AIS-MIAs and IACs, and is helpful for selecting candidates for sublobar resection.Key Points
? IACs appearing as GGNs were often ≥ 12.2 mm in diameter. ? IACs were often ≥ 6.7 mm in solid component diameter. ? The solid components of the IACs often exhibited ≥ -192 HU. ? IACs exhibited air bronchogram more frequently than AIS-MIAs.17.
Small pulmonary nodules: volume measurement at chest CT--phantom study 总被引:13,自引:0,他引:13
Three-dimensional methods for quantifying pulmonary nodule volume at computed tomography (CT) and the effect of imaging variables were studied by using a realistic phantom. Two fixed-threshold methods, a partial-volume method (PVM) and a variable method, were used to calculate volumes of 40 plastic nodules (largest dimension, <5 mm: 20 nodules with solid attenuation and 20 with ground-glass attenuation) of known volume. Tube current times (20 and 120 mAs), reconstruction algorithms (high and low frequency), and nodule characteristics were studied. Higher precision was associated with use of a PVM with predetermined pure nodule attenuation, high-frequency algorithm, and diagnostic CT technique (120 mAs). A PVM is promising for volume quantification and follow-up of nodules. 相似文献
18.
Objective
To investigate the natural course of persistent pulmonary subsolid nodules (SSNs) with solid portions ≤5 mm and the clinico-radiological features that influence interval growth over follow-ups.Methods
From 2005 to 2013, the natural courses of 213 persistent SSNs in 213 patients were evaluated. To identify significant predictors of interval growth, Kaplan-Meier analysis and Cox proportional hazard regression analysis were performed.Results
Among the 213 nodules, 136 were pure ground-glass nodules (GGNs; growth, 18; stable, 118) and 77 were part-solid GGNs with solid portions ≤5 mm (growth, 24; stable, 53). For all SSNs, lung cancer history (p?=?0.001), part-solid GGNs (p?<?0.001), and nodule diameter (p?<?0.001) were significant predictors for interval growth. On subgroup analysis, nodule diameter was an independent predictor for the interval growth of both pure GGNs (p?<?0.001), and part-solid GGNs (p?=?0.037). For part-solid GGNs, lung cancer history (p?=?0.002) was another significant predictor of the interval growth. Interval growth of pure GGNs ≥10 mm and part-solid GGNs ≥8 mm were significantly more frequent than in pure GGNs <10 mm (p?<?0.001) and part-solid GGNs <8 mm (p?=?0.003), respectively.Conclusion
The natural course of SSNs with solid portions ≤5 mm differed significantly according to their nodule type and nodule diameters, with which their management can be subdivided.Key Points
? Pure GGNs ≥10 mm have significantly more frequent interval growth than those <10 mm.? Part-solid GGNs ≥8 mm have significantly more frequent interval growth than those <8 mm.? Management of SSNs with solid portions ≤5 mm can be subdivided by diameter.19.
Guangyu Tao Lekang Yin Dejun Shi Jianding Ye Zhenghai Lu Zhen Zhou Yizhou Yu Xiaodan Ye Hong Yu 《The British journal of radiology》2021,94(1118)
Objective:To investigate the effect of reducing pixel size on the consistency of radiomic features and the diagnostic performance of the downstream radiomic signatures for the invasiveness for pulmonary ground-glass nodules (GGNs) on CTs.Methods:We retrospectively collected the clinical data of 182 patients with GGNs on high resolution CT (HRCT). The CT images of different pixel sizes (0.8mm, 0.4mm, 0.18 mm) were obtained by reconstructing the single HRCT scan using three combinations of field of view and matrix size. For each pixel size setting, radiomic features were extracted for all GGNs and radiomic signatures for the invasiveness of GGNs were built through two modeling pipelines for comparison.Results:The study finally extracted 788 radiomic features. 87% radiomic features demonstrated inter pixel size variation. By either modeling pipeline, the radiomic signature under small pixel size performed significantly better than those under middle or large pixel sizes in predicting the invasiveness of GGNs (p’s value <0.05 by Delong test). With the independent modeling pipeline, the three pixel size bounded radiomic signatures shared almost no common features.Conclusions:Reducing pixel size could cause inconsistency in most radiomic features and improve the diagnostic performance of the downstream radiomic signatures. Particularly, super HRCTs with small pixel size resulted in more accurate radiomic signatures for the invasiveness of GGNs.Advances in knowledge:The dependence of radiomic features on pixel size will affect the performance of the downstream radiomic signatures. The future radiomic studies should consider this effect of pixel size. 相似文献
20.
RATIONALE AND OBJECTIVES: A critical element in determining biologic behavior of pulmonary nodules is volume and temporal volume change. We evaluate variability in nodule volume among readers and measuring methods. MATERIALS AND METHODS: 55 small (<2 cm) lung nodules were measured in long- and short-axis dimensions independently by 4 radiologists, using 3 methods: 1) hard copy, 2) GE Advantage Windows workstation (GE Healthcare, Milwaukee, WI), 3) Siemens IMACS workstation (Siemens Medical Systems, Iselan, NJ). Nodule margin was recorded as smooth, lobulated, or spiculated. Volume was calculated from diameter measurements. Variability in nodule volume was evaluated within each reader, between readers, and across measurement tools. RESULTS: Mean nodule short-axis diameter was 5.3 mm; mean long-axis diameter 7.2 mm. There was statistically significant variation among readers and measurement method for nodule volume. Volume was significantly larger using hard-copy measurements (51.9%-54.1% variation; P < .0001) than either workstation, and not different between workstations. There was greater intraobserver variability in volume using the hard-copy method, and no difference between workstation methods. Volumes based on measurements from one reader were consistently lower than those from other readers (P = < .001, .003, and .02); volume was consistently larger for another reader (P < .0001, .03, and .12). Reader agreement for nodule margin was good to excellent. CONCLUSION: Considerable interobserver and intraobserver variability in measuring nodules exists using hard-copy and computer tools. Since a small change in diameter indicates a much larger change in volume, this may be significant when using early repeat CT to follow small pulmonary nodules. Computer-aided diagnostic tools that reproducibly measure nodule volume are strongly needed. 相似文献